The present invention relates to a method for manufacturing an anti-rotation ring of a scroll type compressor and an anti-rotation mechanism of the scroll type compressor.
Generally, a scroll type compressor has in a housing thereof a fixed scroll including a base plate and a scroll wall formed on the base plate. A rotary shaft is rotatably supported by the housing through a bearing. The rotary shaft has at one end thereof that is adjacent to the fixed scroll an eccentric shaft in an offset relation to the axis of the rotary shaft. The eccentric shaft is rotatably connected to a movable scroll through a bush and a bearing. The movable scroll includes a base plate having a boss to which the eccentric shaft is connected and a scroll wall engaged with the scroll wall of the fixed scroll. An anti-rotation mechanism is provided between the rear side of the base plate of the movable scroll and the housing. The anti-rotation mechanism prevents the movable scroll from rotating on its own axis while allowing orbital movement of the movable scroll. Compression chambers are hermetically formed between the scroll wall of the fixed scroll and the scroll wall of the movable scroll and compression of fluid in the compression chambers are accomplished by the orbital movement of the movable scroll relative to the fixed scroll.
Japanese Patent Application Publication No. 7-151071 discloses an anti-rotation mechanism of a scroll type compressor. The anti-rotation mechanism of this Publication includes a sleeve inserted into a hole of a housing of the compressor and an anti-rotation pin that is press-fitted in a base plate of a movable scroll and in sliding contact with the inner peripheral surface of the sleeve. The scroll type compressor includes a plurality of the anti-rotation mechanisms. The anti-rotation pins moving in sliding contact with the inner peripheral surface of the respective sleeves keep the movable scroll from rotating on its axis while allowing orbital motion of the movable scroll.
Japanese Patent Application Publication No. 62-199983 discloses an anti-rotation mechanism of a scroll type compressor including a plate pin press-fitted in a plate member, a movable pin press-fitted in the base plate of the movable scroll plate and making an orbital motion around the plate pin and an annular ring enclosing one ends of the plate pin and the movable pin, respectively. The plate pin and the movable pin are in line contact with the inner peripheral surface of the annular ring and regulated by the annular ring. Therefore, the anti-rotation mechanism allows the movable scroll to make an orbital motion while inhibiting the rotation of the movable scroll on its axis.
The sleeve disclosed in Japanese Patent Application Publication No. 7-151071 and the annular ring disclosed in Japanese Patent Application Publication No. 62-199983 (such sleeve and annular ring being hereinafter referred to as the anti-rotation ring) are in sliding contact with the pin having a high rigidity. Therefore, the anti-rotation ring needs to be machined with high accuracy and have high wear resistance. Generally, an anti-rotation ring is made by machining a metal bar into a ring, heat treating the ring by quenching and tempering, and then finishing the ring by grinding. However, conventional method for manufacturing an anti-rotation ring has problems in that manufacturing cost is high and manufacturing time is long. Specifically, cutting a metal bar into sections with a specified length and then machining a cut section into a ring shape takes a lot of time and affects the material yield.
The present invention is directed to providing a method for manufacturing an anti-rotation ring of a scroll type compressor that reduces the manufacturing cost and shortens the manufacturing time and an anti-rotation mechanism of the scroll type compressor.